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Starting in fourth grade, Sophia Z. Wastler remembers always pinning her elbows to her side. She never wanted to raise her hand in class to answer a question. Excessive sweating constantly left sweat rings under her arms -- even when it wasn’t hot.

It wasn’t until years later in her early 30s that Wastler mentioned to a doctor that her hands were always sweaty. The doctor then told her about hyperhidrosis, a condition where someone sweats unpredictably and more than needed.

“There were psychological implications that came from the hyperhydrosis. I didn’t know anyone else that this was happening to. From that point on in fourth grade, I felt that I was trying to do a lot of hiding,” said Wastler, a Virginia Beach, Va. resident who is now 36, “What is this thing that was happening to me that no one else had?”

Wastler, a volunteer with the International Hyperhydrosis Society, hopes more people will learn that there are treatments for excessive sweating and not wait years to see a knowledgeable doctor who can help.

Almost 8 million people in the U.S. are estimated to suffer from hyperhidrosis. Of this group, only about 40% have discussed it with a health care professional.

WebMD spoke with dermatologists to discuss what’s normal when it comes to sweating -- and what to do if you’re sweating too much.

Why We Sweat

Regular sweating controls our body temperature and body water. We always sweat to some degree, but it’s more noticeable in hot environments, during exercising, or in times of physical or psychological stress, says Nowell Solish, MD, assistant professor of dermatology at University of Toronto.

We have 2-4 million sweat glands in our bodies, concentrated on the forehead, face, hands underarms, and feet. They produce sweat that's excreted through skin pores to protect us from overheating. As the sweat evaporates, it cools our skin down, says David Pariser, MD, professor in the department of dermatology at the Eastern Virginia Medical School in Norfolk, Va.

Why Some of Us Sweat Too Much

There are two types of hyperhidrosis: Primary hyperhidrosis, which occurs on its own, and secondary hyperhidrosis, which is caused by medications or other underlying health problems. This article focuses on primary hyperhidrosis.

Many people with hyperhidrosis sweat about four times more than normal, although it could be much more or much less. The key is that they sweat a lot at times the body does not need to cool down. Someone could be calm, relaxed, and cool, but still sweat excessively, Solish says.

Researchers aren't sure what causes hyperhidrosis, but doctors think there may be something wrong between the pathways from the sweat glands to the brain. It appears that the glands are too sensitive in people with hyperhidrosis, Solish says.

This problem may be hardwired in some people. Hyperhidrosis tends to run in families -- up to two-thirds of people have it their family, says Solish. And it tends to start in puberty.

Pariser tells WebMD that hyperhydrosis tends to show itself in three to four areas: Under the arms, on the hands, then on the feet, face, and scalp. But excessive sweating can occur all over the body. The sweating is usually symmetric, meaning that both sides of the body are affected similarly.

Unfortunately, he says, “Sweating isn’t something people want to talk about. There’s a stigma with excessive sweating." So, young people often don't get treatment that could help with this embarrassing problem. "When it starts in the teens and they bring it up to parents or doctors, it’s often blown off as a teen whose body is changing," says Pariser. "Then they think there is something wrong when it’s a medical condition that is treatable.”

How Much Is Too Much Sweat?

When it comes to diagnosing hyperhidrosis, it’s so much not the quantity of sweat, but how it impacts the patient’s quality of life, Solish says.

Someone could sweat two times or eight times the normal amounts, but both of those people still have hyperhidrosis, he says.

“It’s too much if you have to think about your sweating and have to act in some way,” Pariser says.

For example, someone with hyperhidrosis may only wear dark clothing, or bring three of the same shirt to work to change during the day to hide the sweat. Some people even stuff paper towels or maxi pads in the underarms. If they have sweaty hands, they may always hold a wet drink to have an excuse not to shake hands in social situations like a cocktail party, he says.

Relief for Excessive Sweating

A number of treatment options are available for those with hyperhidrosis. Dermatologists will start first with prescription strength antiperspirants.

If this doesn’t work, doctors will try iontophoresis, which is treatment with low-level electrical currents, or botulinum toxin (Botox) injections, which block the signal that activates sweat glands. These treatments are repeated when signs of sweating come back. Other drugs that that interfere with sweat glands are available if the preferred treatments don't work, although they may cause more severe side effects. Surgery to remove sweat glands or cut the nerves to glands is a last resort, Pariser says.

As an adult, Wastler no longer has hyperhidrosis in her underarms, but she does have problems with excessive sweating on her palms and feet. She receives Botox injections in her hands, and iontophoresis for her feet.

“I can read the newspaper. I can hold hands with my loved ones. I can hold a tennis racket. You really don’t realize how much you use your hands. In addition to the physical benefits, you also have psychological release like a burden was lifted,” she says.

SOURCES:International Hyperhydrosis Society “Hyperhydrosis Treatments”.Nowell Solish, MD, assistant professor of dermatology at University of Toronto, Canada; board member of the International Hyperhidrosis Society.David Pariser, MD, professor in the department of dermatology at the Eastern Virginia Medical School in Norfolk, Va.; in private practice at Pariser Dermatology Specialists, LTD; founding board member and secretary of International Hyperhidrosis Society. Disclosure: Pariser has done research for Allergan.Ro K, Journal of Vascular Surgery. February 2002; vol 35: pp 382-386.Strutton D. Journal of the American Academy of Dermatology. August 2004; vol 51: pp 241-248.